Conventionally, a machine tool equipped with floating mechanism has been known. In the machine tool, a piston is pressed with an air pressure or spring force to press at a constant pressure various tools such as a grindstone and a drill fit to the tip of the machine tool to machine a workpiece and, at the same time, an error in shape of the workpiece and displacement occurring between the workpiece and a reference workpiece owing to the different working shapes of the different workpieces and misalignment of the workpiece is absorbed by moving the various tools such as the grindstone and the drill (Patent Document 1).